Storage-battery-grid mold and molding process



I. B LITTLE.

STORAGE BATTERY 681D MOLD AND MOLDING PROCESS APPUCAUUN man SEPIZ3,1920.

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UNITED STATES PATENT OFFICE.

IRA. 13. LITTLE, 0F INDIANAPOLIS, INDIANA.

Specification of Letters Patent.

Patented Feb. 15, 1921.

Application filed September 3, 1920. Serial No. 407,808.

To all'whom it may concern. D

Be it known that 1, 11m 13. LITTLE, a citi- 'zen of the United States,residing at Indianapolis in the count of Marion and State of fndiana,have invented new and useful Improvements in Storage-l3attery- GridMolds and Molding Processes, of which the following is a specification.

In the casting of storage batteries much loss and waste has beenexperienced because of the formation of air holes in the frame membersof the grid OJEOSltB the gate, due lar ely to the partial lling of thatportion of t ie mold by metal flowipg through the middle transverseframe members and reaching the far side of the mold before the air inadvance of the metal forming the bottom transverse frame member can fillthe latter and rise in the far side of the mold to the level of saidmiddle transverse member. Under the conditions stated it will readily beseen that the air thns'cut off from escape willrcmain to form pocketsand air-holes thereby rendering the nished product defective andworthless.

Obviously, the grid-mold must fill from the bottom, up, and all of thecomparatively small passages in which the web is formed niust beprogressively filled in order to avoid air pockets in them. Anappreciable length of time is required for the metal to flow from thegate through the small passages of the web and, to keep the fluid metalat a proper temperature so it will not crystallize, and also to providestorage for excess metal coming through the lower passages of the mold wile the upper ones are being filled, has beennecessary in commonpractice to pro- 7 Wide ariser of considerably larger capacity than-thechannel in which the vertical frame member farthest from 'the gate isformed, and this riser-has heretofore can of uniform width and otherdimensions from top to bottom, defined by a score line in the samemanner as the vertical frame member on the gate side is defined from thegate. But the mold thus formed has resulted in a continuplication of myinvention,

one loss of approximately forty per cent. of output. Many su gestionsand experiments in mold-construction have been tried, but without anybeneficial results until the apwhich has entirely overcome thedifficulty, manufacture of over ahundred thousand grids'with myinvention, every one has been double lead grids for trimmed.

so that in the commercially perfect and the former loss has beenentirely eliminated.

The object of my invention is to provide a method to cause all of thevertical channels of the mold to fill sufficiently in advance ofsuccessive upper horizontal channels to avoid the tra ping of air andformation of air holes in t e vertical channels.

Another oby'ect is gradually to reduce the capacit of tie riser from amaximum at a suita 1c distance above the middle horizontal frame channelto such a suitable minimum at its lower end that the riser will takecare of all of the surplus metal and fill to and above said middlechannel before the metal coming in from the other end fills said middlechannel.

The object also is to reduce the vertical line of communication betweenthe riser and adjacent vertical frame channel to so narrow a dimensionthat there is not enough room therein for the formation of objectionableair pockets.

I accomplish the above, and other objects which will hereinafter appear,by the mechanism illustrated in the accompanying drawing, in which- Figure 1, is a view in side elevation of the upper part of a moldingtable with the molds and their appurtenances assembled in operativeclosed )osition. Fi 2 is an inside view of one half of a mo d embodyingmy invention. Fig. 3, is a transverse section of the complete mold onthe line 3-3 of Fig. 2. Fig. 4 is a side view of a casting as it comesfrom the mold, and before it is grids, and Fig. 6, is a section on theline 6-6, of Fig. 4. I Like characters of reference indicate like partsin the several views of the drawing. In the drawing, Fig. 1, 7 is atable to which a'standard 8 is bolted, and to which standard the fixedhalf 9 of the mold is attached. The movable half 10 of the mold issecured to a member 11, hinged at 13 to 9. depending portion 12 of thestandard. The two parts of themold are forced together by a screwadjustment shown in dotted lines 14, and. the mold is opened by graspinghandle 14" and swinging on hinge 13 after the pressure is released.

As the chan'nelsfor grid are the same in both mold-halves 9 and 10,except in correspondingly reversed orthe forming of the der, adescription of one will sufiice for both. it being understood that onlyhalt of a gridforming channel isin each half of the mold.

It will be noted in Fig. 2. that two grids of the form of the finishedcasting shown in Fig. 5, are cast. at one time: also that their abuttingframe members in the mold on the line 3-3, make a channel of double sizewhich heretofore has filled its entire length and part way down theframe channel 15. before the metal coming through the frame channel 16and horizontal web channels 17, have been able to tiIlt'lIaIIneI 15 andconnected riser 18. The riser 18 is required. not only to providestorage for excess metal. but more in order to keep the frame formed inchannel 15, from cooling to a degree that causes or stallization andweakening of the frame. se arate the riser from the adjacent frame y achannel 19 less than half the thickness of the riser. as shown in Fig.3, which makes a finisher] web as shown in Fig. 6, through which theriser is cut from the grids close to the latter, and so narrow thatthere is not room enough for the formation of objectionable air holes tomar the ad'acent frame of the grid.

'lhe dotted lines at the lower portion of riser 18 in Fig. 2, show theextent of the riser channel as same has been heretofore made, and myinvention in part. consists in reducing the area of the riser to aminimum of less than half the former width at the bottom, and ingradually tapering the riser to the former maximum width at anappreciable distance above the line of the channel 15.

The shape, size and location of the gate channel 20, is as usual, and inthe finished casting the gate-portion is defined from the frame of thegrid by a score 21, as a guide in trimming the product.

In the operation of my invention, after the two parts of a mold areclosed together, the interference from warping being minimized byrecessing the adjacent faces at 22. the molten lead is poured in throughthe. gate channel 20 and begins to till the mold channels from thebottom. The melted metal flows through the horizontal channels into thevertical frame channel 15, and into the riser 18. From thence tocompletion, the channels havegmple air outlet, and thus the entirecasting is made without danger of the confinement of' the air that wasin them, to form air-holes in the product. The riser channel affordssuch storage of hot metal in communication with the adjacent verticalframe members-through the restricted channel 19, that impropercrystallization prevented, and the web formed in 19 is so thin that whenout through in trimmingoff the surplus metal concealed air holes thusopened cannot be of any material size.

Having thus fully described my invention, what I claim as new and wishto secure by Letters Patent, is

l. The herein-ilescrihed method of casting battery grids in verticalmolds having vertical channels and horizontal channels connecting thevertical ones, consisting in sup )lying the melted metal to the bottomof the mold. and lilling the vertical channels of the mold sullicientlyin advance of successive upper horizontal channels to avoid trapping airand the formation of air holes in the channels.

2. The herein-described method of casting double battery grids invertical molds having vertical channels and horizontal channels one ofthe lattcr of which at the junction of the two grid'molds is of doublecapacity to form frame-members for two grids. con sisting in supplyingthe melted metal to the bottom of the mold. and filling all of thevertical channels of the mold to the level of said channel of doublecapacity before the latter channel fills, whereby the trapping of airand formation of air-holes in the casting is avoided.

3. In a mold for casting battery grids said mold having verticalchannels and horizontal channels connecting the vertical ones. gatemeans extending to the bottom of the mold, and a riser of graduallydownward reduced area adjacent the far vertical frame member from thegate. f

4. The. herein described mold for casting. battery grids having verticalchannelsland horizontal channels connecting the vertical ones, gatemeans extending to the bottom of the mold, a riser of gradually reducedarea tltljtlwllt the far vertical frame member from the gate connectedwith said frame by a channel the dimension of which trans versely of themold is less than half that of the adjacent frame member.

5. In a double grid-mold having a double frame channel at the junctionof the two grids, a riser having a downwardly tapermg lower end whichtaper begins approximate] opposite said douhle frame channel.

6. n a double grid-mold having a double frame channel at the junction ofthe two grids, a riser having a downwardly tapering lowerend which taperbegins approximatch opposite said double frame channel and it channedconnecting the riser with the mold the dimension of the channel beingless than half of the corresponding dimension of the Signed atIndianapolis, Indiana, this the 28th day of August, 1920.

IRA B. LITTLE.

